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From Mohit Anchlia <mohitanch...@gmail.com>
Subject Re: Atomicity questions
Date Thu, 01 Dec 2011 23:03:44 GMT
Thanks. I'll try and take a look, but I haven't worked with zookeeper
before. Does it use zookeeper for any of ACID functionality?

On Thu, Dec 1, 2011 at 2:55 PM, lars hofhansl <lhofhansl@yahoo.com> wrote:
> Hi Mohit,
>
> the best way to study this is to look at MultiVersionConsistencyControl.java (since you
are asking how this handled internally).
>
> In a nutshell this ensures that read operations don't see writes that are not completed,
by (1) defining a thread read point that is rolled forward only after a completed operations
and (2) assigning a special timestamp (not the timestamp that you set from the client API)
to all KeyValues.
>
> -- Lars
>
>
> ----- Original Message -----
> From: Mohit Anchlia <mohitanchlia@gmail.com>
> To: user@hbase.apache.org
> Cc:
> Sent: Thursday, December 1, 2011 2:22 PM
> Subject: Atomicity questions
>
> I have some questions about ACID after reading this page,
> http://hbase.apache.org/acid-semantics.html
>
> - Atomicity point 5 : row must either be "a=1,b=1,c=1" or
> "a=2,b=2,c=2" and must not be something like "a=1,b=2,c=1".
>
> How is this internally handled in hbase such that above is possible?
>
>

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